+ unsigned explicit_index:1;
+
+ /**
+ * Does this variable have an initializer?
+ *
+ * This is used by the linker to cross-validiate initializers of global
+ * variables.
+ */
+ unsigned has_initializer:1;
+
+ /**
+ * Is this variable a generic output or input that has not yet been matched
+ * up to a variable in another stage of the pipeline?
+ *
+ * This is used by the linker as scratch storage while assigning locations
+ * to generic inputs and outputs.
+ */
+ unsigned is_unmatched_generic_inout:1;
+
+ /**
+ * If non-zero, then this variable may be packed along with other variables
+ * into a single varying slot, so this offset should be applied when
+ * accessing components. For example, an offset of 1 means that the x
+ * component of this variable is actually stored in component y of the
+ * location specified by \c location.
+ */
+ unsigned location_frac:2;
+
+ /**
+ * \brief Layout qualifier for gl_FragDepth.
+ *
+ * This is not equal to \c ir_depth_layout_none if and only if this
+ * variable is \c gl_FragDepth and a layout qualifier is specified.
+ */
+ ir_depth_layout depth_layout;